A manual oral cavity expansion device using a molar tooth as a resistance point comprises a manual pivot device and a pair of expansion arms. Each expansion arm has a first end and a second end, in which the first end is connected with the manual pivot device, and the second end is provided with a molar receiving seat. When the expansion arms are inserted into the oral cavity of a patient and the two molar receiving seats are respectively abutted against multiple upper molar teeth and multiple lower molar teeth, an operator can manipulate the manual pivot device to separate the pair of expansion arms so that the patients oral cavity can be expanded.一種以臼齒為抗力點之手動口腔擴張裝置,其具有:一手動樞轉裝置;以及一對擴張臂,各具有一第一端及一第二端,該第一端係和該手動樞轉裝置連接,而該第二端則設有一臼齒承接座;其中,當該對擴張臂伸入一病患之口腔並使二所述臼齒承接座分別與多個上臼齒及多個下臼齒抵接時,一操作者可藉由操作該手動樞轉裝置使該對擴張臂分離,從而使該口腔張開。100‧‧‧擴張臂110‧‧‧手動樞轉裝置101‧‧‧臼齒承接座102‧‧‧彈性件111‧‧‧握把112‧‧‧套接端113‧‧‧擴張角度指示件
